A communication signal transmitted over a wireless medium consists of a sequence of symbols. The communication signal has an inherent “symbol rate”, corresponding to the rate at which new symbols are transmitted over the medium. Each symbol conveys one or more bits of information, and thus a wireless receiver must be capable of sampling each symbol before the sampled data can be decoded.
In order to sample the signal, receivers generally have one or more analogue to digital converters (ADCs) which are arranged to sample the received signal at a particular sampling rate. To ensure that the receiver samples all received symbols, ADCs are set to sample the received signal at a rate which is significantly higher than the symbol rate of the signal (known as oversampling). In this way, the chances of missing a symbol in the received signal are reduced, and the sample with the highest amplitude can be chosen for any given symbol.
However, the sampling rate of the ADCs has a direct effect on the power consumption of the ADCs and the receiver as a whole. Oversampling a received signal therefore increases the power consumption of the receiver in an undesirable fashion. It would be preferable to find an alternative solution in which the power consumption of the receiver is lower.